Objective To observe the expression stages and characteristics of Plasmodium berghei quiescin sulfhydryl oxidase (PbQSOX). Methods SignalP-5.0 Server and TMHMM Server 2.0 were used to predict and analyze the signal peptide and transmembrane regions of PbQSOX protein. With homologous recombination, PbQSOX-HA tag plasmids were linearized by restriction enzyme NotⅠ, and the linearized plasmids were electroporated into Plasmodium berghei strain and infected mice. The PbQSOX-HA tag Plasmodium berghei was obtained from the peripheral blood of pyrimethamine resistant mice and was identified by polymerase chain reaction (PCR). Schizonts, gametocytes and ookinetes of PbQSOX-HA tag Plasmodium berghei were purified. Western blotting and indirect immunofluorescence assay (IFA) were used to detect the expression stages and characteristics of PbQSOX protein in Plasmodium berghei. Results Bioinformatics analysis showed that PbQSOX protein had a signal peptide, but had no transmembrane region. All the proteins were expressed outside the cell membrane. PbQSOX-HA tag Plasmodium berghei was successfully obtained by homologous recombination of PbQSOX-HA tag targeting plasmid and Plasmodium berghei and confirmed by PCR. The purified schizonts, gametocytes and ookinetes of PbQSOX-HA tag Plasmodium berghei were obtained. Western blotting revealed that PbQSOX protein was mainly expressed in the gametocyte and ookinete stages, and IFA showed that PbQSOX was expressed on the surface of gametocytes, male-gametes, zygotes, retorts and ookinetes. Conclusion PbQSOX is a protein expressed at sexual reproduction stage of Plasmodium berghei, and it is mainly expressed on the surface of gametocytes, male-gametes, zygotes, retorts and ookinetes.